Gang -
Sorry I wasn't able to follow up on this sooner...
The main reason I pushed for using the event type (eg. "click") over
the HTML attribute name (eg. "onclick") was that this is consistent
with similar technologies, such as DOM event listeners. When
registering a listener via the standard DOM APIs, the event type is
identified using the event name (not the "on"-prefixed attribute
name). That is, we specify:
domElement.addEventListener("click",
listener);
Not:
domElement.addEventListener("onclick",
listener);
I believe that the same approach for ClientBehaviorHolder:
behaviorHolder.addClientBehavior("click",
behavior);
And by extension <f:ajax>:
<f:ajax event="click"/>
More closely matches this well-known model.
Another parallel can be found in the W3C XML Events spec:
http://www.w3.org/TR/xml-events/Overview.html#section-listener-element
Where the <listener> has an "event" attribute that specified the
event type (not the on-prefixed attribute name):
<listener event="click" observer="para1"
target="link1" handler="#clicker"/>
Which of course is very similar to the <f:ajax> "event" attribute.
So I think we've got the right approach in place, or at least, we are
in good company with our current approach.